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Query: UMLS:C0079731 (B-cell lymphoma)
 16,671 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We investigated the effect of phorbol myristate acetate (PMA), dexamethasone (Dex) and reagents which raise intracellular cyclic AMP, on the production of plasminogen activator inhibitor type-2 (PAI-2) in human promyelocytic leukemia cell line, PL-21 and on the production of urinary type plasminogen activator (u-PA) in human pre-B cell lymphoma cell line, RC-K8. Cells were cultured in fetal bovine serum free RPMI-1640 containing the test-reagents for 48 hours. PAI-2 and u-PA antigens were measured by ELISA kits. PMA, an activator of protein kinase C (PKC), markedly increased both PAI-2 and u-PA production in each cell line. On the other hand, cAMP increased PAI-2 production in PL-21 cells, but decreased u-PA synthesis in RC-K8 cells. Similar to cAMP, Dex also increased PAI-2 production but decreased u-PA production in RC-K8 cells. Moreover, PMA and cAMP synergistically increased the PAI-2 production. This was verified by Western blot, using a monoclonal antibody against the PAI-2. These two cell lines are, therefore, useful for clarifying the role of A kinase and C kinase on PAI-2 and u-PA synthesis in human hemopoietic cells.
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PMID:[Effect of cyclic AMP and phorbol ester on PAI-2 synthesis in a leukemic cell line PL-21 and on u-PA secretion in a pre-B cell lymphoma cell line RC-K8]. 131 13

In the present article we show that supernatants derived from lipopolysaccharide (LPS) or phorbol 12-myristate 13-acetate (PMA)-stimulated A-20 B cell lymphoma are able to induce polyclonal immunoglobulin (Ig) secretion by normal B cells in a T-cell-dependent manner. This activity could be blocked by neutralizing monoclonal antibodies against interferon-gamma, but not by monoclonal antibodies against interleukin (IL)-2, IL-4, IL-5, IL-6, IL-10 and granulocyte macrophage colony-stimulating factor (GM-CSF) or even a polyclonal antibody against tumor necrosis factor (TNF)-alpha. Furthermore, A-20 supernatants induced the production of measurable amounts of interferon-gamma by normal murine spleen cells and activates natural killer (NK) cells. Fractionation of factor-rich supernatants on a Sephacryl S-200 column revealed that the factor activity is located in the fractions corresponding to a molecular mass of 160-150 kDa and 80-70 kDa. The biological activities found in the A-20 supernatant are very similar to the ones described for the recently cloned human IL-12/NK cell stimulatory factor. These results suggest the existence of a murine analogous factor for the human IL-12 produced by A-20 B cell lymphoma.
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PMID:An activated murine B cell lymphoma line (A-20) produces a factor-like activity which is functionally related to human natural killer cell stimulatory factor. 135 72

The plasminogen activator (PA) activity in various cell lines is suppressed by glucocorticoids. These phenomena are attributed to either a suppression of PA biosynthesis, to an increase of PA inhibitor or to a combination of both. The regulation of urokinase (UK) production in a human pre-B cell lymphoma line, RC-K8, by dexamethasone (Dex) and phorbol myristate acetate (PMA) was investigated. RC-K8 is a cell line which is consistently producing a high molecular weight UK in the conditioned medium (Kubonishi, I., et al: Jpn. J. Cancer Res. 76, 12-15, 1985). The cells were cultured in RPMI-1640 with Dex or PMA for 1-4 days. UK activity was measured using a chromogenic substrate S-2444 and the antigen by an ELISA kit. PAI-1 and PAI-2 antigens were also measured by ELISA kits and the complex between PA and PAI was examined by SDS-PAGE fibrin-zymography. The UK secretion in RC-K8 cells was inhibited by cycloheximide and actinomycin D. PMA at 0.16-1.6 uM up-regulated the UK activity approximately two-fold, parallel with the antigen, whereas Dex at 1-10 uM decreased the UK expression approximately half. These were verified by SDS-PAGE fibrin-zymography. Neither PAI-1, PAI-2 nor PA/PAI complex was detected in the conditioned medium and in the cell lysate. These data suggest that PMA up-regulates the UK secretion without inducing PAIs and the down-regulation of the UK secretion by Dex results from the inhibition of the expression of UK itself but not from the induction of PAIs.
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PMID:Down-regulation of urokinase secretion from a human lymphoma cell line RC-K8 by dexamethasone without inducing plasminogen activator inhibitors. 163 98

ECH408-1 is a murine B cell lymphoma expressing idiotypically and allotypically distinguishable transfected and endogenous IgD. Previously, we demonstrated that this cell line was not growth inhibited by antibodies directed at membrane IgD, but could be inhibited by antibodies which crosslink membrane IgM. Herein, we demonstrate that both anti-mu and anti-delta will cause calcium mobilization in this transfected cell line; this is followed by a period during which antibodies against the alternative isotype are unable to induce significant increases in intracellular calcium concentrations. This phenomenon, called "desensitization," is short-lived, lasting 20 min. We further demonstrate that acute desensitization of these cells by anti-delta has no effect on immediate growth inhibition which is elicited by anti-mu. These data confirm our earlier proposal that the rapid, initial calcium response seen in these lymphomas is not required for the negative signal for growth. Moreover, we also demonstrate that pretreatment of these lymphoma cells with phorbol myristate acetate (PMA) also renders these lymphoma cells temporarily incapable of manifesting a significant calcium signal. Nonetheless, PMA-pretreated B lymphoma cells are not altered in their subsequent sensitivity to anti-mu growth inhibition, nor are they affected in their resistance to inhibition by anti-delta. Our data confirm the proposal that neither the calcium signal nor protein kinase-C activation is involved in the modulation of B lymphoma growth.
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PMID:Lymphoma models for B cell activation and tolerance. VIII. Cross-desensitization by sIgM and sIgD and its effects on growth regulation by anti-isotype antibodies. 232 38

Fifty cases of NHL were studied by scanning electron microscopy to study the possible differences in the surface morphology of tumor cells between T cell and B cell NHL. Acid naphthyl acetate esterase (ANAE) activity test, the stain of antiserum samples of gamma, mu, alpha, kappa, lambda chains with the peroxidase antiperoxidase immune complex method (PAP method) and classification under light microscope were done for all the cases. It was found that the surface morphology of T cell lymphoma cells differed from that of B cell lymphoma. There were a lot of granular protrusions with a few pseudopodia processes on the surface of B cell lymphoma. But on the surface of T cell lymphoma, there were only more or less wrinkles and less granular protrusions. There were long pseudopodia processes on the surface of tumor cells of B cell lymphoma, particularly on the follicular cleaved cell type. The follicular cleaved cell lymphoma had better prognosis with mean survival time of more than four years. There may be other factors responsible for the long survival time. As compared to the lymphoblastic and polymorphic types, the follicular cleaved cell lymphoma has less euchromatin, less mitosis, slower growth rate and higher cohesiveness between tumor cells. The better prognosis is also closely related to the morphology of the tumor cells. With the aid of long processes, the tumor cells are connected with each other to form follicular structure and the movement of tumor cells is restricted. Hence, infiltration and metastasis of the tumor are less pronounced than the lymphoblastic type and T polymorphic cell type.
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PMID:[Scanning electron microscopic examination of 50 cases of non-Hodgkin's lymphoma (NHL)]. 262 Jun 30

In order to examine the process of malignant transformation of human somatic cells, we studied the tumorigenic conversion of an Epstein-Barr-virus-immortalized lymphoblastoid cell line (LCL) derived from a patient with xeroderma pigmentosum (XP) complementation group A. Repeated irradiation of the XP cells, XP7NI, with UV-light and subsequent treatment with 12-O-tetradecanoylphorbol-13-acetate (TPA) resulted in the acquisition of tumorigenicity in athymic nude mice. The tumorigenicity of XP7NI cells was also induced by TPA treatment alone. The tumors formed in athymic mice were of B-cell lymphoma with characteristic histology, cell surface immunoglobulins and an antigen as detected by a B-cell-specific monoclonal antibody (MAb), CD20. The surface immunoglobulins and the HLA type of these tumor cells were identical with those of the parental cells. These malignantly transformed cells retained the same UV sensitivity, serum requirement, colony-forming ability in soft agar, and normal human karyotype as the parental cells. Unlike other tumorigenic lymphoblastoid cell lines, this XP lymphoblastoid cell line provides a unique case in that process(es) leading to tumorigenicity may be induced by UV and TPA without apparent karyotypic changes.
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PMID:Tumorigenic conversion of xeroderma pigmentosum lymphoblastoid cells without karyotypic alteration. 279 36

A comparative study of large cell lymphoma (LCL) (ten B and ten T), Hodgkin's disease (15 cases), and true histiocytic lymphoma (two cases) was undertaken, using formalin-fixed paraffin-embedded tissue sections, a panel of eight antibodies, and one lectin to determine if any particular antibody or immunologic profile could reliably distinguish between these entities. The antibodies used were against Leu-M1, alpha-1-anti-chymotrypsin (alpha-ACT), alpha-anti-trypsin (alpha-AT), lysozyme, kappa, lambda, leukocyte common antigen (LCA), and S-100 protein. The lectin used was peanut agglutinin (PNA). Although Leu-M1 staining was positive in 11 of 15 cases (73%) of Hodgkin's disease, it was also positive in 4 of 10 cases (40%) of T-cell lymphoma, 2 of 10 cases (20%) of B-cell lymphoma, and 1 of 2 cases (50%) of true histiocytic lymphoma. Peanut-agglutinin staining results were similar to Leu-M1. The only staining profile that emerged was the presence of Leu-M1, PNA-, alpha-ACT, and alpha-AT staining in Reed-Sternberg (RS) cells in 11 of 15 cases of Hodgkin's disease. Leu-M1 and its staining pattern is characteristic, but not entirely specific for RS cells, and it was not positive in at least 25% of the cases of Hodgkin's disease in formalin-fixed, paraffin-embedded tissues. The limitations of this antibody and others should be recognized.
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PMID:A comparative marker study of large cell lymphoma, Hodgkin's disease, and true histiocytic lymphoma in paraffin-embedded tissue. 294 20

A B cell lymphoma A20.2J and splenic B cells produced an active material to support the proliferation of an interleukin 2 (IL-2)-dependent T cell line, CTLL-2, by stimulation with both calcium ionophore A23187 and phorbol myristate acetate (PMA). Although the production of the active material was induced by stimulation with A23187 alone in A20.2J cells, both A23187 and PMA were essential for the stimulation of splenic B cells. Neither A20.2J cells nor splenic B cells produced the active material by stimulation with PMA alone. The production was inversely proportional to the concentration of fetal calf serum in culture medium. The active material produced by B cells was indicated to be IL-2 and not B cell-stimulating factor 1 (BSF-1) for the following reasons: 1) the proliferation of CTLL-2 cells in the presence of active material was inhibited by the inclusion of anti-IL-2 receptor or anti-IL-2 in culture medium but not by anti-BSF-1; 2) the material showed no co-mitogenic activity to purified splenic B cells with anti-immunoglobulins and did not support the proliferation of FDC-P2 which are known to grow in the presence of BSF-1; and 3) IL-2 mRNA could be detected in A20.2J and splenic B cells stimulated with A23187 and PMA in Northern blot analysis. Some B cell hybridomas were also shown to produce IL-2 by similar stimulation to A20.2J. Splenic B cells as well as A20.2J cells were able to produce IL-2 by stimulation with anti-immunoglobulins. These results suggest that under certain conditions IL-2 can be produced by splenic B cells, at least some subsets of B cells, and B cell lines.
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PMID:Interleukin secretion by B cell lines and splenic B cells stimulated with calcium ionophore and phorbol ester. 311 82

Following the observation that mouse interleukin 5 (IL5) is active as a B cell growth factor (BCGF) as well as an eosinophil differentiation factor, this work was carried out to test recombinant human IL5 for BCGF activity. A highly active, partially purified batch of recombinant human IL5 was prepared and tested for BCGF activity in four laboratories. This batch gave a 50% endpoint of 1:77,450 in the human eosinophil differentiation assay, 1:983 in the mouse eosinophil differentiation assay and 1:42 in the mouse BCL1 assay, thus demonstrating that, like mouse IL5, human IL5 has cross-species activity. By comparison with the assays in the mouse this batch would be expected to have 50% maximal human BCGF activity of about 1:4000. In each assay a known positive factor was used as a positive control, and there was no inhibitory activity in the preparation. However, despite the activity towards the mouse B cell lymphoma, the results showed no detectable activity in a panel of assays used to identify human BCGF and B cell differentiation factors. These assays included (a) proliferation assays with tonsillar or splenic B cells in the presence of the co-stimulators anti-mu or phorbol myristate acetate; (b) a restimulation assay in which tonsillar B cells are first activated with either Staphylococcus aureus Cowan 1 or a mixture of phorbol dibutyrate and ionomycin, or splenic B cells are first activated with anti-mu; (c) production of immunoglobulin by B cells in a restimulation assay with Staphylococcus aureus Cowan 1; (d) production of immunoglobulin by the Epstein-Barr virus-transformed B lymphoblastoid CESS cell line; (e) the ability to stimulate proliferation of chronic lymphocytic leukemia (B-CLL) cells freshly explanted from three different patients; (f) the ability to stimulate the B lymphoma (L4) cell line and the mature B cell (HBF1) line, and (g) the ability to replace T cells in specific antibody responses. It therefore seems unlikely that recombinant human IL5 is either a growth or a differentiation factor for human B cells, and raises the interesting question of the biological significance of the BCGF activity of this factor in the mouse.
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PMID:Recombinant human interleukin 5 is an eosinophil differentiation factor but has no activity in standard human B cell growth factor assays. 350 Aug 61

Recently, we have described that anti-IgM antibodies profoundly inhibited the growth of BKS-2, an immature B cell lymphoma. In this report, we demonstrated that ionomycin alone at very low concentrations (20 nM) inhibited the growth of BKS-2 cells completely. The levels of intracellular Ca2+ induced by the inhibitory concentrations of ionomycin were comparable to those in anti-IgM-treated cells. The growth inhibition caused by ionomycin was reversed by phorbol 12-myristate 13-acetate and lipopolysaccharide. In addition, the immunosuppressants, cyclosporin A and FK506 conferred significant protection from the negative signal induced by ionomycin. However, either cyclosporin A, FK506 or lipopolysaccharide was not found to have direct effect on ionomycin-induced Ca2+ mobilization in BKS-2 cells. Also, ionomycin augmented the anti-IgM-induced growth arrest in these cells. Furthermore, BKS-2 cells that were exposed to anti-IgM or ionomycin underwent apoptosis as characterized by DNA fragmentation. Thus, the characteristics of growth inhibition induced by ionomycin and anti-IgM appeared to be similar in that phorbol 12-myristate 13-acetate, lipopolysaccharide, cyclosporin A and FK506 caused significant reversal from such negative signals and both ionomycin and anti-IgM induced apoptosis in these cells. Altogether, these results showed that the elevation of intracellular Ca2+ alone was sufficient to inhibit the growth of some B lymphoma cells.
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PMID:Elevation of cytosolic calcium is sufficient to induce growth inhibition in a B cell lymphoma. 769 6


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